The present invention is related to the field of laser processing. A method of laser thermal-force remanufacturing which is used to repair damaged metallic components is especially suitable for repairing deep damaged metallic components.
Laser cladding is a new surface modification technology which is used to fuse the coating material and the surface of the substrate together by high density laser beam to produce the adding cladding layer on the surface of the substrate metallurgical bonding with substrate surface. This process has a significant improvement of wear resistant, corrosion resistant, heat resistant, oxidation resistant and electrical characteristics in the surface of the substrate. Hence, it can modify and repair the surface of the pieces, not only meet the specific performance requirements of the material surface, but also save a lot of valuable elements.
Laser shock peening (LSP), also known as laser peening, is a new method which process the components using mechanical effects of shock wave induced by intense laser. The characteristics of LSP include high-pressure, high-energy, ultra-fast and ultra-high strain rates, etc. Moreover, the shock wave induced by high energy laser pulse can refine grains and enhance the surface properties of metal components. A large number of studies have shown that LSP is an effective method to extend the time of crack initiation, reduce the rate of crack growth and improve the life of components.
When critical aviation components suffer from partial damage, other parts of the components still have good carrying capacity. Hence, extending the service life of the damaged critical components and improving its reliability have become one of core scientific issues of mechanical components remanufacturing. Laser thermal-force remanufacturing technology uses laser cladding to repair and restore the size of the damaged critical components first, and then uses LSP to refine the grains in cladding layers and improve its mechanical properties.
However, the affect depth of LSP under the top surface of metal is 1 mm or less. Hence, when the damaged depth of the metallic component is more than 1 mm, the metallic component will receive no repair out of the LSP affect depth. In laser cladding layers, defects and loose structure caused by thermal effects during laser cladding can result in poor mechanical properties and fatigue failure.